2 Timothy 1:9

Who . . . called us--namely, God the Father (Gal 1:6). The having "saved us" in His eternal purpose of "grace, given us in Christ before the world began," precedes his actual "calling" of us in due time with a call made effective to us by the Holy Spirit; therefore, "saved us" comes before "called us" (Rom 8:28-30). holy calling--the actual call to a life of holiness. Heb 3:1, "heavenly calling" [TITTMANN, Greek Synonyms of the New Testament]; whereas we were sinners and enemies (Eph 1:18; Eph 4:1). The call comes wholly from God and claims us wholly for God. "Holy" implies the separation of believers from the rest of the world unto God. not according to--not having regard to our works in His election and calling of grace (Rom 9:11; Eph 2:8-9). his own purpose--The origination of salvation was of His own purpose, flowing from His own goodness, not for works of ours coming first, but wholly because of His own gratuitous, electing love [THEODORET and CALVIN]. grace . . . given us--in His everlasting purpose, regarded as the same as when actually accomplished in due time. in Christ--believers being regarded by God as IN HIM, with whom the Father makes the covenant of salvation (Eph 1:4; Eph 3:11). before the world began--Greek, "before the times (periods) of ages"; the enduring ages of which no end is contemplated (Co1 2:7; Eph 3:11).

— Jamieson-Fausset-Brown Commentary (public domain)